Searching by groups of users

Hello,

We are trying to construct saved searches at my workplace that
delineate what needs attention and what does not more clearly than
just the ticket status (new, open, etc.) So, I am trying to create a
search of tickets that require attention, which will include all new
tickets as well as any tickets that were last updated by someone
outside of our group, which is a defined group within RT.

Is this kind of search possible? Or do I simply have to make a large
search with a section of LastUpdatedBy != ‘user1’ OR LastUpdatedBy !
= ‘user2’ OR … for 30 or so users?

Thanks!

-Josh